With Apple still keeping decent iPad figures close to its chest, it’s down to thirdparties to make a stab at working out how well its App Store is monetising.

One such is Vimov, the Egyptian developer of 99c app Weather HD.

It’s been working through its data in terms of iPad chart position and sales to extrapolate the scale of the market.

To be honest, it doesn’t seem like a very mathematically robust method as it spreads ten data points to create a single averaged chart for the seven day launch period.

Even taking into account its stated 10-15% error bounding, this is likely to result in a larger overestimation as the launch period would have been much more active in terms of downloads than the current situation.

But it’s all the information we’ve got, so on that basis alone, it’s interesting.

Scale of the situation

In terms of known knowns, Weather HD had sold around 3,500 units prior to and on the iPad launch day and moving between the #3 and #21 spots on the top selling chart.

In total, it did 10,643 sales between April 10 - 16.

Using this data, Vimov reckons the top paid app sells 5,515 copies per day, with the app at #100 selling 209 units.

Accumulating this, it predicts the iPad App Store generates around $370,000 in gross daily revenue (the amazingly exact figure provided is $372,649).

[source: Vimov]